Hollywood starlet and Justin Timberlake's object of affection has revealed how she keeps her killer bod.  She eats half her meal then sends the rest back.  ooohhhhh!

She says, "You have to find balance, especially with what you eat.  I don't live by the idea that you can't allow yourself a treat.   I say:  'Eat things you like but eat them in smaller portions'.  I always cut things in half and send half back."  

Thanks for sharing your diet secrets with us.  Now, when the chocolate cake arrives, only a few bites will be eaten, not the whole thing.

Check out the pictures of Jess as she is snapped leaving rehearsals for "Guys and Dolls"